Perhaps you should try some spelling variations:
thieu sach » chieu sach, thien hach, hieu cach
trung tuan » trung thanh, trung tam, tran tuan
trung cua » truong cua, trung cap, dung cua
hang cong » dang cong, hang nong, bang cong
hieu cac » hieu luc, hieu va, hieu van
cong dan » cong san, cong tan, huong dan
dan than » dan chan, ban than, van than
than cau » toan cau, phan cau, than cap

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((thieu sach) or (hieu cac)) - thanh ((trung cua) OR (trung tuan)) hang cong dan than cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thieu sach) OR (hieu cac)) - thanh ((trung cua) OR (trung tuan)) hang cong dan than cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thieu sach) or (hieu cac)) - thanh ((trung cua) OR (trung tuan)) hang cong dan than cau".
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu sach) or (hieu cac)) - thanh ((trung cua) OR (trung tuan)) hang cong dan than cau*.